You probably won't get a lot of real responses here based on the question. There's understandably a lot of social stigma. I have OCD specifically related to having sporadic violent thoughts. My brain generates these thoughts and I sit on them with recurrent flashes lasting from weeks to years. I will see these flashes any time from once a week to dozens of times a day. I become obsessed with them and find it comfortable to reflect on them. For instance, if I have trouble sleeping, I replay them. In other words, to put myself to sleep, I recreate visions of violent gore I have envisioned. Through decades of meditation and drug use, nothing has matched the feeling I get when returning to a comfortable scene of gore. It's like slipping on a pair of slippers. Remember the smell from the kitchen the first time you remember your mom making cookies? I don't, but I remember my first vision like it was Christmas.
Meditation helps me control them but they will never go away. I am actively a pacifist because when I was a teenager I thought the visions meant I was obsessed with violence and would grow up to be a serial killer and I swore off all violence to prevent it. I maintain my pacifism for the most part, although I've allowed myself to swat mosquitoes in areas where malaria is prevalent and kill ants a few times in the past years, sparingly. I also once defended myself against a spider, which I regret, but I spent 6 months recovering from the illness he had previously given me so I kinda feel like it's justified. I just want to put into perspective how carefully I view life versus how violent the imagery I am forced to view can be. It is not my decision. To be clear in case anyone is concerned, I am aware my decision to kill the spider was intentional and wrong. However, I did make steps to identify the spider as the culprit, who attacked me in my sleep. I weighed the chance that it might attack again and decided to kill it to eliminate this possibility.
It's hard to convey the concept of "intensity". To put it bluntly, my thoughts can be as "innocuous" as overpowering a smaller person, for instance repeatedly punching them while they plead for mercy. I spent years meditating to make my visuals this benign. Most are obviously much more gruesome, it's the kind of thing you can't explain to another person. I used to fantasize benevolently about wringing and severing my testicles in the wheels of a swivel chair to put me to sleep when I was 13, to put this into perspective. It's not like I thought it would feel good, just that it must be done. It's fucking terrifying, and what's really scary is remembering that memory is...fond.
I have never been a violent person. This is just a trick of my brain. What I hate is the idea that there are kids out there that may also misunderstand. I thought I wanted to kill people because I saw them being killed, but my brain was just glitching. That's literally all it is. I abhor violence and always will, it just so happens that thinking about it makes me feel safe. I understand how dangerous and scary that may sound. It is a dangerous and scary disease. But it is better to acknowledge that than hide from it and turn it into reality.
As far as "what's the most intrusive thought I've had", there is no "worst". The intensity isn't the problem, it's the frequency. You ever think about taking out your vans deferens with a pair of rusty pliers? It's 3:29 here and I've thought about it probably 20 or 30 times today. That's what makes it intrusive, frankly. I wish I could see the "worst" and get it over with. There is no "most" or "worst" with this disease, just repetition. Moreso, it's the comfort that is discomforting.